The 59-year-old pop megastar shared a picture of the pair at the Big Apple's Comedy Cellar where they had the crowd in fits of laughter.
In a series of posts on Instagram, she wrote: ''One minute i was Walking into @barneysny like a BOSS for the OFFiCIAL opening of my skin care line @mdnaskin in The US! ... And the next minute i was tagging along with @amyschumer at @nyccomedycellar Making my stand up debut! What a thrill. Finally busted my cherry thank you Amy! (sic)''
Amy added to the photo-sharing app: ''We'd like to thank @nyccomedycellar for taking a chance on our new act. (sic)''
The 'Snatched' actress handed over the microphone and according to various reports, Madonna made jokes about her vagina.
It's not the first time the 'Like a Virgin' hitmaker has performed for Amy.
Last year, Madonna quipped that she gives ''really good'' oral sex as she opened her pal's set at Manhattan's Madison Square Garden.
The 'Vogue' hitmaker delivered an explicit monologue about performing fellatio on men who were planning to vote for Hillary Clinton in November's US presidential election at the start of the comedienne's gig in New York.
She quipped: ''I'd better get off now because someone insanely funny is about to be on this stage, ladies and gentleman, one more thing before I introduce this genius of comedy. If you vote for Hillary Clinton I will give you a b**wjob. I'm really good. I'm not a douche and I'm not a tool. I have eye contact and I do swallow.''
She went on to claim she never receives ''d**k pics'' from men and she no longer sees her manager Guy Oseary - who also represents Amy - because of how quickly the 'Trainwreck' star's success rocketed.
She finished off her monologue by introducing the 36-year-old funnywoman to her audience and admitting she wants to ''one day'' be able to do stand-up like Amy.
She concluded before being ushered off the stage: ''[This] insanely talented woman who I am so jealous of because one day I want to do what she does.''
Madonna returned the favour to Amy after she opened up three of her dates in New York on her 'Rebel Heart' world tour in 2015.
Once a fire fighter, always a fire fighter.
Today (September 14th) marks the 25th anniversary since the album's 1993 release.
Labrinth has teamed up with Sia and Diplo to form a new supergroup: LSD.
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